THE CONSTRUCTION OF A 9-POLE PROTOTYPE FOR SRRC U-10 UNDULATOR

A 9-pole undulator prototype with a magnetic period length of 10 cm wa s designed and constructed to examine the mechanical and magnetic fiel d performance. The hybrid permanent magnet structure was optimized by using 2D ''PANDIRA'' and 3D ''TOSCA'' magnetostatic codes. A half peri od magnet model was also fabricated to verify the magnetic Period leng th field strength on-axis and the transverse field roll-off within 0.1 % in the good field region of +/- 10 mm at a minimum gap of 22 mm. Th e end pole configurations, as equipped with either two tunable permane nt magnetic rotators or steering coil correctors were designed for min imizing the deviation of the magnetic field strength integrals. The ma gnet structures were mounted bn a 2 meter long C-frame support structu re in which the gap could be moved in parallel and phase motion. The f ield characteristics, and measurement results between the adjustable g ap undulator (AGO) and the hybrid adjustable phase undulator (APU) wer e also presented.